Friction shock absorbing mechanism



G. Q. LEWIS FRICTION SHOCK ABSORBING MECHANISM Feb. 23, 1932.

Filed' May 29, 1929 Patented Feb. 23, 1932 i... till FFECE GOODRICH Q.LEWIS, OF WHEATON, ILLINOIS, ASSIGNOR TO W. H. MINER, INC., OF CHICAGO,ILLNOIS, A CORPORATION OF DELAWARE FRIC'I'ION SHOCK BSOEBING MECHANISMApplication inea May ze, 1929. serial No. 366,784.

This invention relates to improvements in friction shock absorbingmechanisms.

In railway practice, in order to insure the efficient and properoperation of Vfriction shock absorbing mechanisms employed in connectionwith railway draft riggingsof cars, it is highly important that thefriction surfaces of such mechanisms be kept free from grit and dirt andalso be protected from the elements so as to maintain the Workingsurfaces in substantially perfect condition. As will be evident,exposure to the elements subjects the friction surfaces to damage due tocorrosion and the collection of dirt and grit on the surfaces quicklyinjures the same by abrasive action and scoring, in addition topreventing proper contact between the surfaces. ln certain types offriction gears employed on railway cars, the friction surfaces are moreor less exposed'and therefore subject to the damagepointed out. This islespecially the case in connection with friction gears of that typehaving movable friction elements arranged about a central friction meansin the foi-m ofa column or post provided with exterior frictionsurfaces.

@ne object of the invention is to prevent damage to the frictionsurfaces of the type of gear indicated, by shielding the frictionsurfaces against exposure.

A further object of the invention is to provide in a friction shockabsorbing mechanism including a friction post and friction shoescooperation with exterior friction surfaces on the post, means forshielding the exterior friction surfaces, wherein the shielding meansprotects the working surfaces of the post inwardly of that portion ofthe post overlapped by the friction shoes in the normal full releaseposition of the mechanism.

A more specific object of the invention is to provide in a frictionshock absorbing mechanism including a central column having eX- teiiorfriction surfaces and cooperating frice tion shoes movable lengthwise ofthe friction surfaces of the column, shielding means for the frictionsurfaces of thecolumn, wherein the shielding means extends rearwardlyfrom the shoes and overlaps the friction surfaces of the column and ismovable with the shoes lengthwise of the column friction surfaces.

Other objects of the invention will more clearly appear `from thedescription and claims hereinafter following.

In the drawings, forming a part of this specification, Figure 1 is ahorizontal, longitudinal, sectional view through theV underframestructure Vat one end of a car, illustrating my improvements inconnection therewith. Figure 2 is a vertical, transverse, sectional viewcorresponding substantially to the line 2 2 of Figure 1. i And Figure 3is a detailed perspective view of a shielding plate employed inconnection with my improved mechanism.

- In said drawings, -10 indicate channel-shaped center or draft sills ofthe railway car underframe, to the inner sides of which are secured theusual front stop lugs 11-11 and rear stop lugs 12-12. The inner endportion of the coupler shank is designated by 13 and a hooded yoke 14 ofwell known form is operatively connected to the coupler shank. A frontmain follower 15 and my improved shock absorbing mechanism are disposedwithin the yoke and the yoke in turn is supported in operative positionby a detachable saddle plate 16 secured to the bottom flanges of thedraft sills.

My improved shock absorbing mechanism comprises broadly a wedge casingA; a combined rear follower and column member B; a pair of frictionshoes C-C; a spring follower D; a. spring resistance E; a` pair ofshielding plates F-F, and a pair of retainer bolts G-G.

The wedge casing A has horizontal top and bottom walls, inwardlydiver-ging side walls and a transverse front end wall bearing directlyon the inner side of the main follower 15. The side walls are suitablyreinforced by horizontally extending webs and are recessed on theirinner sides as indicated at 17-17 to provide pockets in which are seatedwear plates 18-18. The wear plates 18 present opposed interior wedgefaces 19-19 which diverge inwardly of the mechanism.

The combined rear follower and column member B includes a plate-likesection 20 having a forwardly extending post 21 formed integraltherewith. rlhe plate-like section 2O cooperates with the rear stop lugs12 in the manner of the usual rear follower. rlhe post or column section21 has longitudinally e5;- tending outwardly converging frictionsurfaces 22 of V-shape section on opposite sides thereof. The post 21and plate 2O are reinforced by top and bottom horizontally eX- tendingwebs 23-23 on opposite sides thereof.

The friction shoes C-C are two in number and are disposed at oppositesides of the post 21 and cooperate with the loingitudinal` ly disposedfriction surfaces 22 thereof. The two shoes are of similar design, eachhaving a longitudinally disposed J-shaped friction surface 24 on theinner side thereof engaging-with the V-shaped friction surface 2Q at thecorresponding side of the post. On the outer side each shoe has a wedgeface Q5 correspondingly inclined to and cooperating with the wedge face19 at the same side of the casing A. At the inner end each shoe has alaterally inclined abutment face 2G which engages the spring follower D.

The spring follower D is in the form of al relatively heavy rectangularL)late having` top and bottom and vertically disposed side flanges: 2Textending rearwardly therefrom, the vertical side flanges being cut awayat the center as shown in Figure 1 t0 accommodate the outer sides of themembers of the spring resistance means. At the forward side7 the springfollower is reinforced by suitable horizontally and vertically disposedribs as shown. At the rear side, the spring follower presents asubstantially flat, transverse abutment surface against which theforward ends of the members of the spring` resistance bear. The post 21extends through the spring follower, the latter being provided with acentral opening` 28 to accommodate the post, the vopening' 28 being ofan outline corresponding to the cross section of the post and beingslightly larger than the post so as to permit the necessary inwardmovement of thespring follower during compression of themechanismwithout any binding on the post The main body portion of the springfollower is thickened about the opening 28 as indicated at 29. Tirethickened portion 29 is provided with a pair of seats or pockets 30 atopposite sides thereof.` rEhe inner walls of the pockets are inclined asshown and a pair of wear plates 231-31 are seated in said pockets andhave their outer faces in bearing engagement with the inclined abutmentfaces E26 at the inner ends of the friction shoes.

T he'spring resistance means comprises two members disposed at oppositesides of the post, each member comprising an inner, relatively lightcoil and an outer heavier coil. The members of the spring resistance areinterposed between the plate-like section of the combined rear followerand column member B and the spring follower D. The shielding plates Fare disposed at opposite sides of the posts immediately to the rear ofthe friction shoes C-C. The two plates F-F are of similar design, cachbeing of substantially V-shape transverse section so as to interiit withthe corresponding friction surface 22 of the post. At the forward endeach plate F is provided with an outwardlyv and inwardly turned flangesection 32 which, as most clearly shown in Figure l, is disposed betweenthe inner end of the friction shoe at the corresponding side of themechanism and the front side of the spring follower D. The flange 32 isinclined so as to correspond with the inclination of the abutment face2G at the inner end of said shoe and is of such a thickness as tosubstantially occupy the space hetween the abutment face 26 of the shoeand the opposed face of the thickened portion 29 at the front side ofthe spring follower D. As will be evident, each shielding plate F isthus held to the spring follower and the corresponding friction shoe formovement lengthwise of the mechanism therewith. lnasmuch as the innerend of the friction shoe directly engages the flange of the plate F, thesame will be forced inwardly in unison with said shoe. In release of themechanism, when the spring' follower D is forced outwardly, the samewill carry the shielding plates F therewith by engagement with theflanges 32 of the same. rlhe plates F are preferably made of such alength as to at least cover those portions of the friction surfaces ofthe post which are disposed rearwardly of the friction shoes in thenormal full release position of the parts. Sufiicient clearance isprovided between the side walls of Vthe opening 28 of the springfollower D and the friction plates and sutiicient clearance is alsoprovided between the outer edges of the flanges 32 of said plates andthe inner edges of the wear plates 3l to permit the necessary late alseparation of the plates F during inward movement of the same along thedierging friction surfaces of the post. T he outer coils of the springresistance elements are of such a diameter that they engage the plates Fas shown in dotted lines in Fig. 9., thereby yieldingly holding theplates in engagement with the V-shaped surfaces of the post in all positions of the plates. The plates F may be made of any suitable materialbut are prcfer ably in the form of steel plate members. )is will. beevident, these plates may also be made of copper or other material whichdoes not corrode.

As most clearly shown in Figures 2 and 3, the outer edge portions atopposite sides of the plates F are rounded otl as indicated at 35i- 33,thereby preventing the raw edges of the plates from engaging anddamag'in/g the friction surfaces of the post.

The mechanism is held assemblec` and of overall uniform length by thetwo retainer bolts G-G which are disposed at diagonally opposite cornersof the mechanism and extend lengthwise thereof, and have their oppositeends anchored to the plate 20 and the wedge casing A respectively. Theparts are preferably so usted when assembled that the main springresistance E is under initial compression, thereby compensating for wearof the various wedge faces and friction surfaces of the mechanism.

In the operation of my improved shock absorbing mechanism, the wedgecasing A and the combined rear follower and column ber B are movedinwardly, relatively toward each other, thereby settingup a wedgingaction between the wedge faces of t-he member A and the friction shoesforcing the latter laterally inwardly into intimate frictional contactwith the friction surfaces of the post and also carrying the sameinwardly lengthwise of the post. During the inward movement of the shoeson the post, the spring resistance means E will be compressed betweenthe sprinU follower l) and the plate-like follower section 20 of themember B. As the shoes C are forced inwardly along the post 2l, theshielding plates F will be carried therewith, sliding on the frictionsurfaces of the post. Inward movement of the casing A will be limited byengagement of the end wall thereof with the front end of the post,whereupon the actuating force is transmitted directly7 through the postand the plate-like follower section 20 of the member B to the stop lugsof the draft sills, thus relieving the main spring resistance fromexcessive compression.

When the actuating force is reduced in release of the mechanism, theexpansive action of the spring resistanc-e means forces the springfollower outwardly carrying the shoes and wedge casing A therewith. Themain follower l5 will thus be restored to thenormal full releaseposition. As the spring follower D is carried outwardly, the shieldingplates F will be carried therewith by engagement of the flanges 3Q.thereof with thev follower and will be returned to the release positionshown in Figure l.

As will be evident from the preceding description taken in connectionwith the drawings, the shielding plates F fully protect the exteriorworking friction surfaces of the post in all positions of the partsduring operation of the shoclr absorbing mechanism. Inasnuch as theseplates are at least as great in length as the active port-ions of thefriction surfaces rearwardly of the-shoes, they fully cover the same andprevent entrance of dust, dirt and grit between t-he same and thefriction surfaces of the post. It is further pointed out that theshielding plates protect the friction surfaces of the post from theelements, thereby preventing corrosion of the same. It will beappreciated that the collection of dirt and grit on the frictionsurfaces of the post is detrimental to the proper operation of thefriction gear, lirst because the foreign matter between the frictionsurfaces of the post and shoes will prevent proper contact between theseparts and any gritty matteid will cause damage to the friction surfacesof the post and shoes by scratching and scoring. It is further obviousthat corrosion of the friction surfaces renders the same inetlicient.

I have herein shown and described what I now consider the preferredmanner of carrying out my invention, but the same is merely illustrativeand I contemplate all changes and modifications that come within thescope of the claims appended hereto.

I claim:

l. In a friction shock absorbing mechanism, the combination with acolumn member having exterior friction surfaces extending lengthwisethereof; of friction shoes cooperating with said friction surfaces;neans yieldingly opposing relative movement of the shoes and column;means movable toward and away from said column for forcing the shoesinwardly against the same and lengthwise of the friction surfacesthereof; and shielding means for the friction surfaces of the columnrearwardly of the shoes, said shielding means being at least as great inlength as the active friction surface rearwardly of the shoes, and saidshielding means being' movable with the shoes.

2. In a friction shock absorbing mechanism, the combination with afollower; of a column having longitudinally disposed enterior frictionsurfaces, said column and follower being relatively movable toward andaway from each other; friction shoes engaging the friction surfaces ofthe column and having wedging engagement with the follower; a springfollower engaging the inner ends of the shoes; spring resistance meansopposinginward movement of the spring follower and shoes; and shieldingmeans for the friction surfaces of the post extending rearwardly fromthe spring follower, said means being movable with the friction'shoes.

3. In aV friction shock absorbing mechanism, the combination with acolumn member having longitudinally disposed friction surfaces; of afriction shoe cooperating with each friction surface of the post; meansfor forcing said shoes against the post and lengthwise thereof; meansyieldingly opposing movement of the shoes; and a shielding plateoverlying each friction surface of the post adjacent each shoe, saidshielding plate being slidable on said friction surface and movable withthe corresponding shoe.

l. In a friction shock absorbing mechanism, the combination with acolumn member having longitudinally extending exterior frictionsurfaces; of friction shoes slideable lengthwise of the column; meansyieldingly opposing relative movement of the shoes and column; means forforcing the shoes inwardly against the column and lengthwise thereof;and cover means normally completely overlying the active frictionsurfaces of the column inwardly of the friction shoes, said cover meansbeing slideable over said column friction surfaces.

5. In friction shock absorbing mechaanism, the combination with a columnhaving` longitudinally disposed exterior friction surfaces; of afriction shoe having sliding engagement with each friction surface ofthe column; means for forcing said shoes against the column and movingthe same lengthwise thereof; spring resistance means opposing inwardmovement of the shoes; a spring follower interposed between the springresistance means and the shoes, said spring follower ha Ying an openingthrough which the post extends; and protecting plates fitting thefrction surfaces of the column, each of said plates extending throughthe opening of the spring follower and having an out turned end fiangeinterposed between the spring follower and the corresponding shoeadapted to be engaged by the shoe, whereby said plate is moved inwardlyin unison `with the shoe during compression of the mechanism, saidflange having shouldered engagement with the spring follower whereby theplate is moved outwardly in unison with the spring follower duringrelease of the mechanism.

6. In a. friction shock absorbing mechanism, the combination with afriction column having exterior friction surfaces extending lengthwisethereof; of cooperating friction elements movable lengthwise of saidsurfaces; and means inwardly of said elements protecting the fictionsurfaces of the column, said means and elements together in full releaseposition thereof completely overlapping the active portions of thefriction surfaces of the friction column.

In witness that claim the foregoing I have hereunto subscribed my namethis 27th day of May 1929.

GOODRICH Q. LEVIS.

